디밍을 고려한 VLC 통신방식 시뮬레이션 연구

Abstract

Recently, several research groups have performed researches on indoor visible light communication (VLC) system using illumination LEDs. Compared with the conventional lightings such as fluorescent or incandescent lamps, the illumination LED lighting is very useful due to its advantages such as efficiency, low power consumption, environmental friendliness, eye safety and no governmental regulation for radiation. Since the VLC system is assumed to be used for lighting and communication simultaneously, the dimming control function will be inevitable. Therefore, it is natural to consider a VLC system capable of dimming with data communication at the same time. In this thesis, I have described the development of the simulation program and shown the simulation results on a VLC system which transmits PPM and NRZ-OOK data streams with PWM dimming control signal. Also, I have calculated the illumination distribution, the optical power distribution, the signal waveforms, the eye diagrams and the BER curves. The proposed simulation program is simple to use as it is equipped with the graphical user interface for input parameters. This simulation program has been implemented using MATLAB and SIMULINK. I found that the PWM-based VLC system can act as a communication system independent of dimming control. I expect that the developed program will be improved for studying the outdoor optical wireless communication system operating at different optical wavelengths, considering physical outdoor channel effects.